If this assay fails to detect a deletion and suspicion for alpha thalassemia remains elevated (e.g. low MCV, confounding presence of iron deficiency, low percentage of Hb S in sickle-cell trait, heterozygous beta thalassemia, Hb H disease with a two-alpha globin gene deletion), then it is possible that a non-deletion type of alpha thalassemia could be present. Such variants can be detected using our Alpha-globin Gene Sequencing assay (test code AGSQ), which determines the DNA sequence of both alpha1 and alpha2 globin genes and detects the presence of point mutations that result in alpha thalassemia.
There are four alpha globin genes per diploid genome, with two genes located on each chromosome. The most common molecular abnormalities that cause alpha thalassemia are alpha globin gene deletions, which can result in either one or two alpha globin gene deletions per chromosome. Although point mutations that cause alpha thalassemia occur in the alpha globin genes, these are not common and may be found in individuals from inbred populations.
This test detects seven deletions that cause alpha thalassemia in various worldwide populations. These are:
1) Rightward (- alpha 3.7): one alpha globin gene deletion. (alpha thal-2). It is the most common type of alpha thal-2 deletion found in numerous populations worldwide such as in African, Mediterranean and Far Eastern populations. This test will detect the common and Hawaiian variants of this deletion.
2) Leftward (- alpha 4.2): one alpha globin gene deletion. (alpha thal-2). This deletion is much less prevalent than the rightward deletion and occurs in multiple populations.
3) Southeast Asian (- - SEA): Two alpha globin gene deletion. (alpha thal-1). Found in Southeast Asian populations, mostly China.
4) Filipino (FIL): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Filipinos and Hawaiians. Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains.
5) Thai (THAI): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Southeast Asian individuals (Thailand). Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains
6) Mediterranean (MED): Two alpha globin gene deletion. (alpha thal-2). Occurs in individuals with Mediterranean backgrounds.
7) 20.5 Kb: Two alpha globin gene deletion. (alpha thal-2). Found in various Mediterranean and Central Asian populations.
The most clinically significant situation arises when each parent is a carrier of a 2 alpha-globin gene deletion in cis (--/aa). Fetuses of such couples are at 25% risk for hydrops fetalis. Fetuses of couples where one partner is a carrier of a 2 alpha-globin gene deletion and the other is a carrier of a single alpha-globin gene deletion are at 25% risk for Hb H disease (--/-a).
This test is often used to assess whether a low MCV is caused by the inheritance of alpha-thalassemia either alone or in combination with iron deficiency and/or beta-thalassemia.
Note: This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Heparinized samples. Tissue flasks with poorly confluence cultures. Insufficient amount of amniotic fluid or chorionic villi
Reference Interval
Negative. No alpha globin gene deletions detected.
Additional Information
If this assay fails to detect a deletion and suspicion for alpha thalassemia remains elevated (e.g. low MCV, confounding presence of iron deficiency, low percentage of Hb S in sickle-cell trait, heterozygous beta thalassemia, Hb H disease with a two-alpha globin gene deletion), then it is possible that a non-deletion type of alpha thalassemia could be present. Such variants can be detected using our Alpha-globin Gene Sequencing assay (test code AGSQ), which determines the DNA sequence of both alpha1 and alpha2 globin genes and detects the presence of point mutations that result in alpha thalassemia.
There are four alpha globin genes per diploid genome, with two genes located on each chromosome. The most common molecular abnormalities that cause alpha thalassemia are alpha globin gene deletions, which can result in either one or two alpha globin gene deletions per chromosome. Although point mutations that cause alpha thalassemia occur in the alpha globin genes, these are not common and may be found in individuals from inbred populations.
This test detects seven deletions that cause alpha thalassemia in various worldwide populations. These are:
1) Rightward (- alpha 3.7): one alpha globin gene deletion. (alpha thal-2). It is the most common type of alpha thal-2 deletion found in numerous populations worldwide such as in African, Mediterranean and Far Eastern populations. This test will detect the common and Hawaiian variants of this deletion.
2) Leftward (- alpha 4.2): one alpha globin gene deletion. (alpha thal-2). This deletion is much less prevalent than the rightward deletion and occurs in multiple populations.
3) Southeast Asian (- - SEA): Two alpha globin gene deletion. (alpha thal-1). Found in Southeast Asian populations, mostly China.
4) Filipino (FIL): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Filipinos and Hawaiians. Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains.
5) Thai (THAI): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Southeast Asian individuals (Thailand). Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains
6) Mediterranean (MED): Two alpha globin gene deletion. (alpha thal-2). Occurs in individuals with Mediterranean backgrounds.
7) 20.5 Kb: Two alpha globin gene deletion. (alpha thal-2). Found in various Mediterranean and Central Asian populations.
The most clinically significant situation arises when each parent is a carrier of a 2 alpha-globin gene deletion in cis (--/aa). Fetuses of such couples are at 25% risk for hydrops fetalis. Fetuses of couples where one partner is a carrier of a 2 alpha-globin gene deletion and the other is a carrier of a single alpha-globin gene deletion are at 25% risk for Hb H disease (--/-a).
This test is often used to assess whether a low MCV is caused by the inheritance of alpha-thalassemia either alone or in combination with iron deficiency and/or beta-thalassemia.
Note: This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.
CPT Codes
81257
LDT or Modified FDA
Yes
LOINC Codes
21687-9
Available Stat
No
Test Code
ATHL
Test Group
Thalassemia
Performing Lab
Medical Genomics - Molecular Diagnostics
Performed
Run 1x per week as needed
Methodology
PCR and gel electrophoresis
Remarks
Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.
Heparinized samples. Tissue flasks with poorly confluence cultures. Insufficient amount of amniotic fluid or chorionic villi
Specimen Preparation
Do not centrifuge, do not freeze, Refrigerate samples and ship at room temperature.
Reference Interval
Negative. No alpha globin gene deletions detected.
Synonyms
Alpha thalassemia-1
Alpha thalassemia-2
Reported
7-14 days
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Additional Information
If this assay fails to detect a deletion and suspicion for alpha thalassemia remains elevated (e.g. low MCV, confounding presence of iron deficiency, low percentage of Hb S in sickle-cell trait, heterozygous beta thalassemia, Hb H disease with a two-alpha globin gene deletion), then it is possible that a non-deletion type of alpha thalassemia could be present. Such variants can be detected using our Alpha-globin Gene Sequencing assay (test code AGSQ), which determines the DNA sequence of both alpha1 and alpha2 globin genes and detects the presence of point mutations that result in alpha thalassemia.
There are four alpha globin genes per diploid genome, with two genes located on each chromosome. The most common molecular abnormalities that cause alpha thalassemia are alpha globin gene deletions, which can result in either one or two alpha globin gene deletions per chromosome. Although point mutations that cause alpha thalassemia occur in the alpha globin genes, these are not common and may be found in individuals from inbred populations.
This test detects seven deletions that cause alpha thalassemia in various worldwide populations. These are:
1) Rightward (- alpha 3.7): one alpha globin gene deletion. (alpha thal-2). It is the most common type of alpha thal-2 deletion found in numerous populations worldwide such as in African, Mediterranean and Far Eastern populations. This test will detect the common and Hawaiian variants of this deletion.
2) Leftward (- alpha 4.2): one alpha globin gene deletion. (alpha thal-2). This deletion is much less prevalent than the rightward deletion and occurs in multiple populations.
3) Southeast Asian (- - SEA): Two alpha globin gene deletion. (alpha thal-1). Found in Southeast Asian populations, mostly China.
4) Filipino (FIL): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Filipinos and Hawaiians. Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains.
5) Thai (THAI): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Southeast Asian individuals (Thailand). Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains
6) Mediterranean (MED): Two alpha globin gene deletion. (alpha thal-2). Occurs in individuals with Mediterranean backgrounds.
7) 20.5 Kb: Two alpha globin gene deletion. (alpha thal-2). Found in various Mediterranean and Central Asian populations.
The most clinically significant situation arises when each parent is a carrier of a 2 alpha-globin gene deletion in cis (--/aa). Fetuses of such couples are at 25% risk for hydrops fetalis. Fetuses of couples where one partner is a carrier of a 2 alpha-globin gene deletion and the other is a carrier of a single alpha-globin gene deletion are at 25% risk for Hb H disease (--/-a).
This test is often used to assess whether a low MCV is caused by the inheritance of alpha-thalassemia either alone or in combination with iron deficiency and/or beta-thalassemia.
Note: This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.
CPT Codes
81257
LDT or Modified FDA
Yes
LOINC Codes
21687-9
Ordering
Available Stat
No
Performing Lab
Medical Genomics - Molecular Diagnostics
Performed
Run 1x per week as needed
Methodology
PCR and gel electrophoresis
Reported
7-14 days
Additional Information
If this assay fails to detect a deletion and suspicion for alpha thalassemia remains elevated (e.g. low MCV, confounding presence of iron deficiency, low percentage of Hb S in sickle-cell trait, heterozygous beta thalassemia, Hb H disease with a two-alpha globin gene deletion), then it is possible that a non-deletion type of alpha thalassemia could be present. Such variants can be detected using our Alpha-globin Gene Sequencing assay (test code AGSQ), which determines the DNA sequence of both alpha1 and alpha2 globin genes and detects the presence of point mutations that result in alpha thalassemia.
There are four alpha globin genes per diploid genome, with two genes located on each chromosome. The most common molecular abnormalities that cause alpha thalassemia are alpha globin gene deletions, which can result in either one or two alpha globin gene deletions per chromosome. Although point mutations that cause alpha thalassemia occur in the alpha globin genes, these are not common and may be found in individuals from inbred populations.
This test detects seven deletions that cause alpha thalassemia in various worldwide populations. These are:
1) Rightward (- alpha 3.7): one alpha globin gene deletion. (alpha thal-2). It is the most common type of alpha thal-2 deletion found in numerous populations worldwide such as in African, Mediterranean and Far Eastern populations. This test will detect the common and Hawaiian variants of this deletion.
2) Leftward (- alpha 4.2): one alpha globin gene deletion. (alpha thal-2). This deletion is much less prevalent than the rightward deletion and occurs in multiple populations.
3) Southeast Asian (- - SEA): Two alpha globin gene deletion. (alpha thal-1). Found in Southeast Asian populations, mostly China.
4) Filipino (FIL): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Filipinos and Hawaiians. Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains.
5) Thai (THAI): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Southeast Asian individuals (Thailand). Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains
6) Mediterranean (MED): Two alpha globin gene deletion. (alpha thal-2). Occurs in individuals with Mediterranean backgrounds.
7) 20.5 Kb: Two alpha globin gene deletion. (alpha thal-2). Found in various Mediterranean and Central Asian populations.
The most clinically significant situation arises when each parent is a carrier of a 2 alpha-globin gene deletion in cis (--/aa). Fetuses of such couples are at 25% risk for hydrops fetalis. Fetuses of couples where one partner is a carrier of a 2 alpha-globin gene deletion and the other is a carrier of a single alpha-globin gene deletion are at 25% risk for Hb H disease (--/-a).
This test is often used to assess whether a low MCV is caused by the inheritance of alpha-thalassemia either alone or in combination with iron deficiency and/or beta-thalassemia.
Note: This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Heparinized samples. Tissue flasks with poorly confluence cultures. Insufficient amount of amniotic fluid or chorionic villi
Result Interpretation
Reference Interval
Negative. No alpha globin gene deletions detected.
Additional Information
If this assay fails to detect a deletion and suspicion for alpha thalassemia remains elevated (e.g. low MCV, confounding presence of iron deficiency, low percentage of Hb S in sickle-cell trait, heterozygous beta thalassemia, Hb H disease with a two-alpha globin gene deletion), then it is possible that a non-deletion type of alpha thalassemia could be present. Such variants can be detected using our Alpha-globin Gene Sequencing assay (test code AGSQ), which determines the DNA sequence of both alpha1 and alpha2 globin genes and detects the presence of point mutations that result in alpha thalassemia.
There are four alpha globin genes per diploid genome, with two genes located on each chromosome. The most common molecular abnormalities that cause alpha thalassemia are alpha globin gene deletions, which can result in either one or two alpha globin gene deletions per chromosome. Although point mutations that cause alpha thalassemia occur in the alpha globin genes, these are not common and may be found in individuals from inbred populations.
This test detects seven deletions that cause alpha thalassemia in various worldwide populations. These are:
1) Rightward (- alpha 3.7): one alpha globin gene deletion. (alpha thal-2). It is the most common type of alpha thal-2 deletion found in numerous populations worldwide such as in African, Mediterranean and Far Eastern populations. This test will detect the common and Hawaiian variants of this deletion.
2) Leftward (- alpha 4.2): one alpha globin gene deletion. (alpha thal-2). This deletion is much less prevalent than the rightward deletion and occurs in multiple populations.
3) Southeast Asian (- - SEA): Two alpha globin gene deletion. (alpha thal-1). Found in Southeast Asian populations, mostly China.
4) Filipino (FIL): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Filipinos and Hawaiians. Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains.
5) Thai (THAI): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Southeast Asian individuals (Thailand). Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains
6) Mediterranean (MED): Two alpha globin gene deletion. (alpha thal-2). Occurs in individuals with Mediterranean backgrounds.
7) 20.5 Kb: Two alpha globin gene deletion. (alpha thal-2). Found in various Mediterranean and Central Asian populations.
The most clinically significant situation arises when each parent is a carrier of a 2 alpha-globin gene deletion in cis (--/aa). Fetuses of such couples are at 25% risk for hydrops fetalis. Fetuses of couples where one partner is a carrier of a 2 alpha-globin gene deletion and the other is a carrier of a single alpha-globin gene deletion are at 25% risk for Hb H disease (--/-a).
This test is often used to assess whether a low MCV is caused by the inheritance of alpha-thalassemia either alone or in combination with iron deficiency and/or beta-thalassemia.
Note: This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.
Administrative
CPT Codes
81257
LDT or Modified FDA
Yes
LOINC Codes
21687-9
Complete View
Available Stat
No
Test Code
ATHL
Test Group
Thalassemia
Performing Lab
Medical Genomics - Molecular Diagnostics
Performed
Run 1x per week as needed
Methodology
PCR and gel electrophoresis
Remarks
Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.
Heparinized samples. Tissue flasks with poorly confluence cultures. Insufficient amount of amniotic fluid or chorionic villi
Specimen Preparation
Do not centrifuge, do not freeze, Refrigerate samples and ship at room temperature.
Reference Interval
Negative. No alpha globin gene deletions detected.
Synonyms
Alpha thalassemia-1
Alpha thalassemia-2
Reported
7-14 days
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Additional Information
If this assay fails to detect a deletion and suspicion for alpha thalassemia remains elevated (e.g. low MCV, confounding presence of iron deficiency, low percentage of Hb S in sickle-cell trait, heterozygous beta thalassemia, Hb H disease with a two-alpha globin gene deletion), then it is possible that a non-deletion type of alpha thalassemia could be present. Such variants can be detected using our Alpha-globin Gene Sequencing assay (test code AGSQ), which determines the DNA sequence of both alpha1 and alpha2 globin genes and detects the presence of point mutations that result in alpha thalassemia.
There are four alpha globin genes per diploid genome, with two genes located on each chromosome. The most common molecular abnormalities that cause alpha thalassemia are alpha globin gene deletions, which can result in either one or two alpha globin gene deletions per chromosome. Although point mutations that cause alpha thalassemia occur in the alpha globin genes, these are not common and may be found in individuals from inbred populations.
This test detects seven deletions that cause alpha thalassemia in various worldwide populations. These are:
1) Rightward (- alpha 3.7): one alpha globin gene deletion. (alpha thal-2). It is the most common type of alpha thal-2 deletion found in numerous populations worldwide such as in African, Mediterranean and Far Eastern populations. This test will detect the common and Hawaiian variants of this deletion.
2) Leftward (- alpha 4.2): one alpha globin gene deletion. (alpha thal-2). This deletion is much less prevalent than the rightward deletion and occurs in multiple populations.
3) Southeast Asian (- - SEA): Two alpha globin gene deletion. (alpha thal-1). Found in Southeast Asian populations, mostly China.
4) Filipino (FIL): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Filipinos and Hawaiians. Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains.
5) Thai (THAI): Two alpha globin gene deletion. (alpha thal-2). Found predominantly in Southeast Asian individuals (Thailand). Fetuses homozygous for this deletion are usually aborted due to the deletion of genes that encode embryonic zeta chains
6) Mediterranean (MED): Two alpha globin gene deletion. (alpha thal-2). Occurs in individuals with Mediterranean backgrounds.
7) 20.5 Kb: Two alpha globin gene deletion. (alpha thal-2). Found in various Mediterranean and Central Asian populations.
The most clinically significant situation arises when each parent is a carrier of a 2 alpha-globin gene deletion in cis (--/aa). Fetuses of such couples are at 25% risk for hydrops fetalis. Fetuses of couples where one partner is a carrier of a 2 alpha-globin gene deletion and the other is a carrier of a single alpha-globin gene deletion are at 25% risk for Hb H disease (--/-a).
This test is often used to assess whether a low MCV is caused by the inheritance of alpha-thalassemia either alone or in combination with iron deficiency and/or beta-thalassemia.
Note: This test was developed and its performance characteristics determined by the Clinical Laboratories at the Medical Center at UC San Francisco. It has not been cleared or approved by the U.S. Food and Drug Administration.
